1. Field
The present disclosure relates to a driving force distribution apparatus for a four-wheel drive vehicle.
2. Description of the Related Art
As a driving force distribution apparatus for a four-wheel drive vehicle, Japanese Unexamined Patent Application Publication No. 2-261947, for example, discloses an apparatus including a hydraulic clutch disposed in a driving force transmission path that couples a driving force of a driving source mounted in the vehicle to front and rear wheels or to left and right wheels, wherein the driving force of the driving source can be variably distributed to the front and rear wheels or to the left and right wheels after regulating pressure of working oil that is supplied to the hydraulic clutch through an electromagnetic solenoid valve disposed in a hydraulic supply mechanism.
In the above-mentioned apparatus, the electromagnetic solenoid valve disposed in the hydraulic supply mechanism include a spool, which is slidably held in a sleeve and which has one end biased by a plunger and the other end biased by a spring disposed in a damper chamber, and the damper chamber is filled with the working oil to suppress pulsations of the oil pressure. In the technique disclosed in Japanese Unexamined Patent Application Publication No. 2-261947, the electromagnetic solenoid valve including the damper chamber is immersed in the working oil.